Tin can container



S. MUSHER TIN CAN CONTAINER April 20, 1843.

Filed May 2, 1939 IRON SHEET TIN PLATE ALCOHOLIC OR WATER EIOLUBLE ANTIOXYGENS EXTRACTED FROM FINELY DIVIDED CEREALS, SEEDS AND SIMILAR VEGETATIVE MATERIALS WITH OR WITHOUT A PERVIOUS CARRIER OR BINDER SUCH AS PARAFFIN OR FAT T I N PLATE L m R E T A M PIECES OF SUBJECT T ANTIOXYGENIC INTERIOR SURFACING TIN PLATE FOR MAKING CAN m N E G Y X m T N A INVENTOR fiz'a'ney Mas/2e! BY f SPRAY A ORNEY Q E 5 R 2 O O we 2 8m Mm CF 9 7 R o T c A R T X E m IL 0 H O C L A ANTIOXYGENIC LIQUOR Patented Apr. 20, 1943 TIN CAN CONTAINER Sidney Musher, New York, N. Y., assignor to Musher Foundation, Incorporated, New York, N. Y.,'a. corporation of New York Application May 2, 1939, Serial No. 271,261'

6 Claims. (o1. zinc-64) The present invention relates to the treatment of tin containers used for packaging of oxidizable organic materials and preferably for containers where no inner lacquer is used.

An object of this invention is the production of antioxygenic tin containers which will retard deterioration of packaged organic materials and particularly of glyceride oil containing organic materials.

A further object is the production of antioxygenic tin containers which will resist development of corrosion.

A still further object is the production of antioxygenic tin containers which will retard prooxygenic action as may arise because of metallic contamination'due to the tin and also by reasoon of the pro-oxygenic activity of the different metals in the plated or coated can construction.

Still further objects and advantages will appear from the more detailed description set forth more detailed description is given by way of illustration and explanation only, and not by way' of limitation, since various changes therein may be made by those skilled in the art without departing from the scope and spirit of the present invention.

In accordance with this invention, antioxygenic materials obtained from the constituents of the finely divided unbleached cereals and seeds are applied to tin containers either to the inner walls or surfaces .of those containers or to the sheet metal from which such containers are fabricated.

Such antioxidants should desirably not be applied as part of hard resinous lacquer or varnish coatings, but should be applied in such manner as to be available for direct action upon the oxidizable material, either by direct contact thereto or through a pervious film such as paraflin, waxes, hydrogenated fats, etc.

It is necessary for the proper carrying out of this invention for the antioxygenic materials to be available for reaction with the packaged product in orderto retard the oxidative deterioration of the packaged product and also to retard the pro-oxygenic effect of the metal as well as a slightlyelevated temperature as at 100 F., removing the residual fibers and starch from the dissolved alcohol soluble fraction by filtration,

centrifuging, siphoning or similar means and then boiling off the alcohol, preferably undera reduced pressure in order to obtain an alcohol soluble extract.

This alcohol soluble extract contains sugar and organic phosphorus and may be satisfactorily utilized in accordance with this invention.

The preferred method for carrying out this invention is to apply the alcoholic extract to a felt or other roller by passing the roller through a bath of the alcoholic extract and, by the proper use of a doctor on the roller, then permitting a sheet of metal to be passed over the surface, of the roller whereby the metal sheet picks up a thin. film of the alcoholic extract.

For example, theremay be applied to the metal from 0.005% to 1% by weight of the antioxygenic extract against the weight of the tin plate.

The sheet metal may then be made up into cans or similar containers and there may be present on the'i'nner surface of a 1 1b. can or container from 0.05 gram. to 2.0 grams of the be dissolved in a suitable volatile solvent such as alcohol, water, -etc., or it may be allowed to remain in the alcohol and then applied to the tin by spraying on the tin 'or to the inner surfaces of the can, subsequently permitting the alcohol, water or other solvent to evaporate oli, using heat where desired. There will remain on the surface of the metal or at the inner surfaces of the can a thin film of the extracted, starch and sprayed on to the inner surface of that can in an atomized condition. A thin film of the antioxygenic material is thus applied to the inner sunfaces of the can. This application is preferably made immediately before the can is used for packaging purposes.

In the drawing is diagrammatically illustrated the can structure of the present invention and the method of producing the same:

Figure 1 is a fragmentary transverse sectional view of a can wall upon an enlarged scale showing the application of the interior antioxygenic surfacing.

Figure 2 is a transverse sectional view upon a smaller scale as compared to'Figure 1 showing the complete can enclosing a granular or divided material such as coffee subject to oxidative deterioration.

Figures 3 and 4 are side sectional views illustrating two methods of applying the interior antioxygenic surfacing to the can.

In Figure 1 the metal plate In of iron or steel has been dipped in or coated with the tin I I and forms a can wall, the entire can being shown in Figure 2. As shown in Figure 1 the interior surface of the can is' provided with an antioxygenic coating i2.

Referring particularly to Figure 2, the metal wall top and .bottom indicated by A are interiorly surfaced by the coating B and receive finely divided, granular or liquid oxidizable material C which may contain a glyceride oil or an essential oil. I

In Figure 3 is shown the method for applying the antioxygenic surfacing to a tin plate which is to be used for making a can. As shown, the container I3 carries the oily, viscous or liquid antioxygenic material H.

Theiapplication roller l5 may carry a felt or similar material IE which passes through the antioxygeni-c material I4 upon rotation of the roller IS. The doctor blade II will remove the excess and the roller will then contact with the plate 18 moving in the direction I 9.

The plate may less desirably be dried or heated to cause adherence or permanentizing of the surfacing and if desired the surfacing maybe applied to .both sides of the can.

In Figure 4 the can 20 having a side wall 2! and a bottom 22 with the top not yet applied may be sprayed by the nozzle 23 with the antioxygenic spray 24 upon the interior surface 25. The covers may be independently treated before closure.

In accordance with this invention, the corrosion of tin can containers is very markedly reduced and under those circumstances, the coating lacquers may be reduced or replaced by the antioxygenic substances described with decreased corrosion of the tin plate and withsuperior preservation of the can'contents. This is particularly important in the packaging of fruits and other aqueous materials, and particularly-with those products that are normally high in acid, and where corrosion occurs most readily. V

The cans contaning the surfacing of the antioxygenic material are particularly important in the packaging of the glyceride oil containing organic compositions and also for essential oil containing organic compositions. For example, these antioxygenic cans may desirably be used for the packaging of such products as salmon, sardines, mackerel and herring, whether packed in tomato sauce, oil, vinegar, mustard, or other material, tuna fish, cod fish, cod fish cakes and other fishery products, ham, tongue, corned beef, and other ery products such as sardines, salmon, herring, etc., it has been observed that this treatment ap plied to the cans before packaging retards not only the development of rancidity, but also protein decomposition of the packaged fishery products.

In the case of the packaging of coffee, the staleness in the coffee is retarded separate from the development of rancidity in the coifee.

This treatment may be applied to the cans even where the packaged product is subsequently pack-' aged under vacuum because after the can has been opened and the vacuum released, the deterioration of the packaged product ensues and such deterioration may be retarded by the treatment of the can as indicated.

It is particularly desirable to use for this purpose the alcohol soluble extracts as these extracts are sufliciently heavy and viscous to adhere to the surfaces of the can and may not be readily removed therefrom.

The alcohol or water soluble extracts of the cereal and seed germs or their deoiled residues in finely divided form may also be satisfactorily employed for this purpose, such as the methyl or ethyl alcoholic extract of finely divided wheat germ, deoiled wheat germ residue, rice germ or rice bran, corn germ, peanut germ, etc.

The oil containing seeds and preferably the finely divided de-oiled or de-fatted seeds and nuts such as those obtained following the expression or extraction of the oils therefrom may also be utilized for alcoholic or aqueous extraction in the manner indicated above and employed in accordance with this invention. Among the seeds that may be thus utilized are soya beans, peanuts, cottonseed, and particularly their deoiled residues obtained following the expression or extraction of the oils therefrom and such residues containing less than 10% total glyceride oil. Cacao beans, and particularly the de-oiled or defatted residue of roasted cacao nibs, and cacao shells may also be employed for alcoholic or aqueous extraction.

Example I j Tin plate was run over felt rollers, the bottom of which was dipped into a trough containing the carbohydrate and phosphorus containing, viscous-ethyl alcoholic extract of finely divided dry milled maize flour with the alcohol having rating oil. the ethyl alcohol at 65 C. in a vacuum" oven. The alcoholic extract thus obtained was cooked meats, fats and oils, such as lard, hydrogenated shortening, butter, oleomargarine, cottonseed salad oil, olive oil, etc. These containers may also be used for the packaging of dairy products including evaporated. and condensed milk, ice cream mix, powdered whole milk, etc., roasted ground coffee, canned fruits and fruit juices including orange Juice, grapefruit juice, canned peaches, pears, pineapples, grapefruit, oranges, etc., pork and beans, tomato soup and other canned soups and broths, canned vegetables such as asparagus, beans, etc.

In connection with the packaging of fatty fish- The coffee was tested after the opening of the cans at intervals over a period of 20 days and it was observed that the coffee packed in the cans thus treated was substantially resistant to the development of staleness and was much improved in keeping quality over coffee packed in a similar aged product need not be in direct and continuous contact with the antioxygenic material atthe surface of the can. For example, in the packaging of coffee, every particle of the coffee is not in intimate contact with the can or with the antioxygenic material at the surface of the can, but

nevertheless .the portion of the coffee removed from direct contact with the can walls is materially improved in keeping quality. m

It has surprisingly been observed that this treatment of the can often gives much superior results to those obtained even where the antioxygenic material is added to and admixed throughout the body of the. packaged organic composition.

Another desirable feature of this invention is I that when, for example, the antioxidant is added directly to the, oxidizable composition and admixed therein, it would require special labeling whereas under the conditions of this invention, a desirable improvement in keeping quality is obtained without necessitating any change in the labeling of that composition.

Moreover, in the case of the packaging of coffee, the mixture of 1.0 gram of the alcoholic extract throughout the body of approximately 450 grams of the coffee does not give as great an improvement in the keeping quality as where the 1.0 gram of the extract is applied to the surface of the can in the packaging of the 450 grams of the coffee.

- Example II The tin plate was prepared as in Example I using the ethyl alcoholic extract of deoiled soya decomposition as determined by AOAC method for NH3 decomposition as compared with sardines similarly packed, treated and held in regular un- Six sardines were first treated cans not containing the antioxygenic material as a surfacing thereon.

In the above experiment, it was particularly surprising that even though the extract at the interior surface of the tin was not in immediate and direct contact with the sardines, as there was an inner layer of the oil between the extract and the sardines, nevertheless the treatment served to retard deterioration in the sardines.

There may also be utilized in accordanc with this invention the concentrated water extract of the finely divided cereals, seeds or nuts or their deoiled residues and particularly of finely divided unbleached maize, barley and oats.

This extract is desirably prepared using 1 part by weight of the cereal such as maize flour and 9 parts by weight of wate using water that has been adjusted in pI-I to an acidity of between 5.0 and 6.5. The maize flour was thoroughly mixed with the water at 135 F. for 30 minutes. The mixture was allowed to stand for about 3 hours and the undissolved maize portion then was tion. The supernatant water portion containing the water soluble antloxygens present in these flours was evaporated, preferably under a reduced pressure at about 135 F. to obtain a concentrated extract containing at least 30% total solids and preferably or more total solids.

The extract thus obtained may be applied to tin plate or sprayed on the interior surfaces of the tin cans in the manner indicated with the alcoholic extract. In addition, where these cans are steamed out immediately prior to filling, the steam may be caused to entrain a smallamount of the concentrated water extract in order to apply to the innersurfaces of the tin can from 0.05 gram to 5.0 grams by weight. of the concentrated water extract on the solids weight of that extract to each 1 pint can, or a proportionate quantity for larger or smaller cans The deterioration of the fruit Juices andthe fruits is not directly related to the decomposition of the glyceride oils and fats such as shortenings, lard, etc., but nevertheless this treatment serves to retard the deterioration of the fruits and fruit juices as well as of other packaged organic compositions and particularly of the oil containing organic compositions, whether the oil is present in emulsified form as in the case of evaporated milk, or whether it is thoroughly distributed throughout the body of the organic composition as in the case of orange oil dispersed in canned orange juice. The treated cans will also protect hydrogenated oil, lard,

shortening or salad oil,

It is much less preferable to use the cereal or seed flours in place of their extracts. Where the flours are employed, however, it is desirable to dissolve or disperse them in paraffin or hydrocarbon wax or in an hydrogenated fat or to mix them with an alcoholic or similar extract of the cereal or seed or with a glyceride oil and apply in the manner indicated.

There may also be utilized the spice residues and particularlythe alcohol soluble extracts obtained therefrom.

The effectiveness of these antioxygenic materials becomes particularly pronounced when the organic composition, after packaging, is heated in the can to a temperature of at least 175 F. and preferably to a temperature of over 200 F. and desirably to between 225 F. and 250 F.

Example III the tin in a thin film on the can. Freshly ex pressed mackerel oil was then brushed over the surface of the tin plate. In one case the treated: plate containing the mackerel oil brushed over its surface was placed in an oven at 200 F. for 10 minutes and in theother case the treated removed by centrifuging, decantation or filtra- 7d plate was left unheated. The mackerel oil wasextracted at regular intervals and peroxide values were taken. I

Rancid. Slightly rancid.

Other vegetative antioxidants may less desirably be employed and particularly the water or alcohol soluble carbohydrate and .organic phosphorous and nitrogen containing antioxidants present in these vegetative materials as removed by a solvent having the formula XOH where X is hydrogen or a low molecular weight aliphatic radical.

Other solvents such as acetone or hydrocarbon solvents may be utilized but these are much less desirable for application in accordance with this invention. For example, the acetone soluble extract of maize flour or deoiled soya flour may be employed in an analogous manner.

Where desired, and where the tin can container I is lacquered, the antioxygenic extract may be applied at the end of the lacquering operation and while the lacquer is still tacky or sticky.

In any event, the antioxygenic material must be at the surface of the metal and must not be thoroughly admixed with the lacquer since lacquers upon solidification form a surface film that does not permit the antioxygenic properties to be imparted to the packaged organic composition. Where a pervious material such as paraflin, waxes, hydrogenated fat or similar waxy material is applied to the surface of the can material, the antioxygenic extract may be previously admixed with such pervious material. For example, a mixture comprising 10% of the ethyl alcohol extract of unbleached pulverized oats and 90% of paraflin wax may be applied to the interior surface of the can by either a roller operation as described or by spraying the compostion on the inner surface of the can. Where desired, due to the pervious nature of these coating compositions, the antioxygenic extract may seemployed directly on the inner surfaces of the tin can and then the inner surfaces may be treated further by paraflin or other waxy material.

Under the conditions outlined above, where the lacquers are applied to the can and the lacquers are baked on the can at a temperature of about 300 F. to 400 F., at the close of the baking operation and while the lacquer is still tacky,

a small amount of the antioxygenic extract referred to may be sprayed into the inner surfaces of the can. This extract will adhere to the surface of thelacquer and at the same time it will be available for direct contact with the packaged product. p

A particularly important feature of the invention is the fact that the antioxygenic substances need not be mixed with the product that is packaged. This avoids any direct contamination or the introduction of any extraneous or foreign materials and also avoids special labeling.

In addition, the presence of the antioxygenic material when on the walls of the container may be used in much smaller quantities than would be necessary where the antioxygenic material is directly incorporated into the oxidizable composition itself.

Where the can containing the oxidizable or- 'ganlc composition is ubjected to an elevated temperature following the packaging thereof, such as to a temperature of at least 200 F. and desirably to a temperature of 225 F. or above, it is possible to use combinations of special materials to develop antioxygenic activity.

It is, for example, possible to use combinations of water soluble carbohydrates with lecithin or similar phosphorus containing compounds. These materials are not particularly effective for retarding oxidative decomposition of the packaged organic compositions unless the heat treatment is applied whereby they develop substantial 'antioxygenic activity, I U

For example, 10% of lecithin'obtained from crude soya bean oil, crude corn oil, etc., or from the refining of other vegetable oils may be added to glucose and thoroughly admixed therein. Even though the lecithin is not soluble in the glucose, a

satisfactory suspension of the lecithin in the glucose can be made and where desired that mixture may be reduced in viscosity to the desired liquidity by theaddition thereto of water, so- I In place of glucose there may be employed other water soluble carbohydrates or sugars including sucrose, dextrose, cane or beet sugar,

sugar syrup or mother liquors or residues ob-,

tained from them.

In place of lecithin there may be employed other similar phosphorous containing compounds such as cephalin and there may also be utilized phosphoric acid and the phosphates.

Along with sugars may also be employed compositions from the group of the polycarboxylic aliphatic acids such as tartaric acid, citric acid,

maleic acid, etc.; hydroxy aryl compounds of the nature of hydroquinone such as hydroquinone, alphanaphthol and other polyhydroxy benzenes, amino-phenols, etc.; nitrogen containing materials and preferably the proteins such as casein, albumen, etc., and the amino acids such asparagine, tyrosine, etc.

Surprisingly, some of these compounds, such as lecithin alone may be satisfactorily employed without the addition thereto of the other components. Where lecithin, for example, is used for coating on tin plate by first rendering it sufiiciently liquid by dissolving it in-a small quantity such as in from 1 part to 5 parts of glyceride oil and paraiiin wax, and where that plate is used for the production of tin can containers in the packaging of organic compositions containing water soluble carbohydrate materials or containing protein materials, and then subjected to an elevated temperature treatment of in excess of 200 F.,the lecithin, although it itself is recognized as losing its antioxidant action when heated to temperatures in excess of C. nevertheless develops marked antioxidant activity' when used for the inner liner of cans for the packaging of organic compositions that are then subjected to temperatures in excess of 200 F.

These materials may or may not have antioxidant activity when first applied to the can, but. when subjected to the elevated temperature in the presence of the organic packaged composition, marked antioxygenic effect will be developed.

Theremay less preferably be employed sugars alone and particularly the substantially crude The present application is a continuation in part of the co-pendingapplication, Serial No. 69,296 filed March 1'7, 1936, and application, Serial No. 105,155, filed October 10, 1936, which first mentioned application is inturn a continuation in part of application, Serial No. 13,743, filed March 29, 1935, which matured into Patent No. 2,038,752. The last mentioned application Serial No. 13,743 was co-pending with application, Serial No. 3,876 filed January 28, 1935, which matured into Patent No. 2,026,697.

The present application is also a continuation in part of application, Serial No. 282,080 filed June 30, 1939, which matured into Patent 2,176,030 dated October 10, 1939.

Having described my invention, what I claim is:

l; A tin can container carrying on the inner surfaces thereof a very thin film of only a'viscous, oily, alcohol free, alcoholic extract of finely divided vegetative substance capable of substan-- tially protecting oxidizable organic compositions contained therein.

2. A tin can container carrying on the inner surfaces thereof a very thin film of only a viscous, oily, alcohol free, alcoholic extract of flnely divided seed material capable of substantially protecting oxidizable organic compositions contained therein.

a. A tin can container carrying on the inner surfaces thereof a very thin film of .only an antioxygenic stabilizing material capable of substantially protecting oxidizable organic compositions contained therein, said stabilizing material consisting of a viscous, oily, alcohol free ethylalcoholic extract of pulverized whole oats.

4. A tin can container carrying on the inner surfaces thereof a very thin film of only an antioxygenic stabilizing material capable of substantially protecting oxidizable organic compositions contained therein, said material consisting of a.

viscous, oily, alcohol free ethyl alcoholic extract of de-oiled soya bean fiour, said flour containing a small amount of soya bean oil.

5. A tin can container carrying onthe inner surface thereof a very thin film of only an antioxygenic stabilizing material capable of substantially protecting oxidizable organic compositions contained therein, said stabilizing materials consisting of a viscous, oily, alcohol free alcoholic extract of a pulverized cereal.

6. A tin can container carrying on the inner surface thereof avery thin film of only an antioxygenic stabilizing varnish material capable of substantially protecting the oxidizable organic composition contained therein, said stabilizing material consisting of a viscous, oily, alcohol free a finely divided cereal.

ethyl alcoholic extract of SIDNEY MUSHER. 

